1. Field of the Invention
This invention relates to the general field of vacuum packaging and particularly but not exclusively to the vacuum packaging of components for use in assemblies.
2. Discussion of Prior Art
It is known in various industries, and in particular those light industries involving small consumer goods, to vacuum package articles. These articles are generally of a small, relatively light nature and may be vacuum packaged to help protect them from scratches, cracks or other damage during transit or to prevent oxidisation. Examples of such goods are small screwdrivers, drill bits and batteries. These goods are generally packaged so that they are situated in a viewable position between a transparent plastics film and a thin cardboard backing part. The goods may be removed relatively easily from the packaging by pressing the goods through the thin cardboard backing part.
In heavy industries involving the packaging of larger heavier articles, such as components for assembly, it has been traditional to pack the components into boxes, cases or crates filled with a soft packaging material to prevent damage in transit when the components are moved from one workshop or factory to another for assembly. In industries, for example the aerospace industry, where it is important that certain components are not subjected to even small scratches, the packaging of components has traditionally been a labor intensive and time consuming task, the packaged components also taking up relatively large amounts of space. To counter these problems associated with traditional packaging methods, some heavy industries have attempted to use the vacuum packaging methods employed by light industry. However it was found that the thin cardboard backing parts used for vacuum packaging light consumer goods were not suitable for packaging the heavier components for transporting them to assembly lines.
When vacuum packaged using the thin cardboard backing, heavier components caused the backing part to bend and distort, making it extremely difficult to transport the packaged components. Also the backing part was prone to split or rupture due to those distortions, resulting in damaged components.
To prevent damage to the components, attempts were then made to use thicker backing parts in the vacuum packaging process, but these attempts have generally failed as conventional vacuum packaging machines do not generate enough suction to allow a relatively thick backing plate to be positioned between the vacuum packaging machine and the component to be vacuum packaged.
Consequently heavy industry has had either to rely on traditional methods of packaging as described above, or to vacuum package components using a thin cardboard backing part and then glue the thin backing part on to a rigid backing board so that the components may be transported. This latter method of packaging is not a significant improvement over the traditional methods as the process is still time consuming due to the necessity of having to glue two backing parts together and wait for the glue to fix. Furthermore it is difficult to remove components packaged in this way as a component generally cannot be pushed through the backing part due to the rigid backing board. It is usually necessary to cut the component out via the transparent plastics cover, which has the disadvantages of risks to personnel involved in cutting out the component, and also the risk of scratching the component as it is being cut out. The risk of scratching the component is considerable as the transparent plastics cover has been tightly wrapped around the components, due to the vacuum packaging technique. In applications such as the aerospace industry, it is highly undesirable to use this method as any slight scratches may result in a structural weakness and render a component unusable.